Femtocells burst onto the scene in the U.S. with great fanfare in 2007. Yet two years later, significant consumer adoption seems nowhere in sight, despite trials by AT&T, Sprint, and others. So what happened? What’s really holding back the rollout of femtocell technology and consequential adoption by consumers? The simple answer is the operators.

Operators could have gone to market with a solution in 2007, but they declined because there was no standard for femtocell technology. They had the misconception that if femtocells were standardized, consumers could merely purchase them and plug them into the network, and inter-vendor competition would be “game on.”

There are many standardized interfaces, such as the IUB interface between the basestation and the core in a 3G architecture. But history has taught us that operators have never been able to simply buy basestations from multiple vendors, plug them into any network, and have them work.

Instead of toiling away with standards, operators could have rolled out a high-capacity 3G HSPA network for urban and suburban environments built on femtocells where the basestation is partly paid by, housed by, climate-controlled by, and powered by the consumers. Consumers even would have paid for the backhaul.

From an operator perspective, consumers would have paid for everything that goes into building a network. By not taking advantage of this seemingly undeniable market opportunity two years ago, the operators may have played right into the hands of the big macrocell manufacturers who were protecting their revenue streams by delaying femtocells through a standards process.

Now during the second half of 2009, Long-Term Evolution (LTE) is driving the issue. Operators will need to deploy picocells and femtocells as a cost-effective alternative to more expensive macrocell sites, especially when it comes to delivering LTE to where subscribers will use it the most—indoors.

Operators in the U.S. are moving cautiously with trials. However, progress toward femtocells as a mass-market proposition is incremental and slow. Why? Again, the answer lies with the operators. The rollout of femtocell technology carries a variety of complex and never-before-seen challenges for an operator on a network planning and management level.

On average, an operator typically installs 300 extra basestations into its macro 3G network during each financial quarter. That operator has complete control over this process in terms of planning, choice of site, and deciding when the basestation goes live.

Flash forward into the near future and imagine that the cost for femtocells drops below $200—a generally agreed upon price point by analysts that will drive mass consumer adoption. Special promotions during the holiday season especially will generate large consumer purchases in November and December.

In this scenario, an operator potentially faces tens of thousands of new miniature 3G sites going live over a single weekend. These new sites could be anywhere, from a single femtocell in a house in the country to 50 or more units in a single apartment building, generating multiple and overlapping 3G signals.

Such a scenario creates a bubble of radio interference as multiple femtocell signals disrupt the macro network, impeding performance and impairing the customer experience. Only careful management and optimization of network resources will address this interference and ensure seamless integration between the femto and macro layers.

The sheer scale of a femtocell layer will place new stresses and strains on a network architecture. As consumers plug in their femtocells, network managers will have to confront sudden spikes in bandwidth demand across different parts of their network at different times.

The arrival of femtocells as a mass-market consumer proposition means that operators are no longer in exclusive control of their own network planning. This reality is a daunting prospect for them because it requires a new dimension in intelligent, dynamic, continually updated network planning and management.

This reality at least partially explains why operators are deploying femtocells at the current, methodical pace. Unless they appropriately forecast and plan for the various capacity challenges that femtocells will place on their network, they place the performance of their entire network at risk.